Faultfinder.



T; B. ANDERSON.

FAULTFINDER.

APPLICATION FILED NOV. 26, 190B.

gmaem ioz flea dare ziwrsan' Quota,

' UNITED STATES PATENT OFFICE.

THEODORE E. ANDERSON, OIE SUPERIOR, WISCONSIN, ASSIGNOR OF ONE-FOURTH TOCHARLES R. FRIDLEY, ONE-FOURTH TO FRED SPEECHLY, AND ONE-FOURTH TO SOLONI4. PERRIN, ALL OF SUPERIOR, WISCONSIN.

. FAULTFINDER.

Specification of Letters Patent.

Patented Sept. 21,1909.

Application filed November 25, 1908. Serial No. 464,457.

at Superior in the county of Douglas and State of \Visconsin, haveinvented certain new and useful Improvements in Faultfinders, of whichthe following is a specification.

The present invent-ionrelates to means for finding faults in electriccables or lines, and the primary objectis to provide a. portable devicethat is very active and effective, is compact, and simple, neithercontaining nor including intricate mechanism of any kind, said meansfurthermore being of a character that will permit the successful use bypersons comparatively inexperienced in elec-' trical matters, as itrequires no involved readings of a highly technical character, and nointricate computations and deductions.

The preferred form of construction is illustrated in the accompanyingdrawings, wherein Figure l is a perspective View of the device, showingcertain of the features diagrammatically. Fig. 2 is a diagrammatic view,illustrating the manner in which the device is used.

Similar reference mnnerals designate corresponding parts in all thefigures of the drawings.

' A base 3 is employed of hard rubber, wood, fiber or other suitablematerial, and on said base is located a resistance Wire 4 of knownquantity, preferably German silver. This wire is disposed in zigzagrelation upon the upper face of the base and has marked-contact points 5disposed at predetermined distances apart and indicated by scale marks,as shown. The terminals of the resistance wire are connected to bindingposts 6, to which a faulty cable can be connected, as hereinafterexplained- Another set of binding posts 7 is employed, which posts arerespectively connected as illustrated at 8-to the terminals of theresistance wire 4. To the binding posts 7 areconnected the terminals ofa common telephone receiver 8*. Still another set of binding posts 9 aremounted on; the base, these binding posts being electrically connectedas'illustrated at 10. To one of the binding posts 9 is attached aflexible insulated Wire 11 having a contact element 12 at its free end,

which element can be placed in engagement with any of the marked contactpoints 'of the resistance wire. The other binding post 9 constitutesmeans for electrically connecting to the contact element 12, one pole 13of a source of electrical energy 14, such as a set of dry batteries. theother pole of said source of electrical energy being so arranged that itcan be grounded as illustrated at 15.

The resistance wire :4 is of a predetermined length, for example. fiftyinches, and the contact points are scaled preferably at one inch. Inorder to locate the trouble in a cable or line, the exact length of saidcable is first determined, and one end thereof is connected to the endof a return cable. For instance, in Fig. 2, if the cable 16 is groundedat 17, the end of said cable 16 is connected, to a return cable, 18. Theends of the pair of cables are then attached to the binding posts 6. Onepole of a six or eight dry cell batter as 14,;is connected to one of thehinding posts 9, and the other pole is grounded. The receiver 8 is thenplaced to the ear and the contact element or fceler 12 is moved alon theresistance or bridge wire l until no disturbance is heard in thereceiver. To determine the point at which the ground occurs, thelength'of the grounded cable 113 is multiplied by two, giving the lengthof the entire cable 16 and 18. This result is multiplied by the numberon the scale at the silent point and divided by fifty, the entire lengthof the resistance or bridge wire. The result will be the distance infeet from the fault finder to the point of trouble. If the circuit iscrossed, one side of the circuit that is in trouble is grounded, anotherwire or cable of an ungrounded and uncrossed set is connected to theother side of the crossed pair, and the instrument is-used as statedabove. The same rule and formula will apply to toll lines by using milesinstead of feet. It will be understood that with this structure, the

be of the same size, but any sized wire can be measured, provided thewires of the pair are equal 1n size.

exceedingly simple, inasmuch as there is no complicated machinery ormechanism, and furthermore none of the elements are apt to become brokenor deranged. However should the necessity arise, any element may beeasily duplicated at slight cost. The

cables or the pairs of wires in the cable must- It will be evident thatthis structure is structure furthermore is so small and light that itcan bereadily carried about and can be placed in an overcoat ocket.Experience has demonstrated that t e results obtained are absolutelyaccurate, and if desired can be figured down to inches. In addition tothis any person who has a rudimentary knowledge of mathematics can usethe deviceas there are no complicated readings or mathematicalcomputations required. The structure isbased upon the 'fact that where.a wireis grounded, the current does not all .escape into the ground,and if given a chance .will flow over wires both Ways from the point ofground. This fact is made use of by .tying one end of the faultyconductor to a working conductor of the same denoi'nina tion, and tyingthe other ends of the conductors to the fault finder. then flow bothways from the ground and at some point, the flow will be equal or ofequal resistance. The present device locates this point by indicatingthe point of no disturbance- WVhen the point of no disturbance isfound,-the total length of'the two conductors is multiplied by thenumber of inches;

stood that various changes in the size, shape,

proportion and minor details of construction, may be resorted towlthoutdepartlng from the splrit or sacrificing any of the advantages ofthe invention.

Having thus fully described my invention,

The current will what I claim as new, and desire to secure by LettersPatent, is 5-- 1. In a fault finder of the type disclosed, thecombination with a portable support of a predetermined length, ofresistance material carried-by the support, a scale located along theline. of resistance material and comprising a series of consecutiveindicating symbols disposed at spaced points and arranged in oppositedirections from the ends of the line to an intermediate point thereonmeans for connecting a faulty conductor on opposite sides of the faultto the terminals.

of the resistance material, an indicator connected to the terminals ofthe resistance materiaha source ofelectrical energy, and means forgrounding one pole of said source of electrical energy and engaging theother pole with the resistance at the different points indicated by thescale.

2. In a fault finder of the type disclosed, the combination with asupport, of a line of resistance wire mounted thereon in a zigzagrelation and having marked contact points located at predetermineddistances apart, a set of consecutive indicating numerals arranged onthe support at the contact points and extending consecutively from theends to the center of the resistance wire, means for connecting a faultyconductor to the ends of the resistance wire, a telephone connected tothe ends of the wire, a source of electrical energy, means for groundingone pole of said source, and means for engaging the other pole with theresistance wire atthe different indicated contact points.

In testimony whereof I hereunto afiix my signature in the presenceof'two witnesses.

THEODORE E.

- Witnesses:

WALTER W. SAYAGE, S. J. MATHER.

ANDERSON.

